No role for quality scores in systematic reviews of diagnostic accuracy studies

Potential role of proteomics in the diagnosis of lymphoma: a meta-analysis

Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS) has been approved for identifying biomarkers and diagnosing many diseases such as lymphomas. It is arguable whether the SELDI technique has its value of diagnostic accuracy for lymphomas. The purpose of our study is to determine the diagnostic accuracy of SELDI-TOF-MS for diagnosing lymphomas. The Cochrane Central Register of Controlled Trials, MEDLINE, Pub Med, EMBASE, the Chinese Biomedical Literature Database, the China Academic Journals Full-text Database, and the Chinese Scientific Journals Database were searched systematically for potential studies. Reference lists of included studies and review articles were also reviewed. All studies that reported data on patients with a confirmed diagnosis of lymphomas and that compared the measurement of SELDI-TOF-MS with pathology standard were considered for inclusion. Eleven studies were included in the systematic review. The ranges of the diagnostic value of SELDI-TOF-MS for lymphoma were as follows: sensitivity (SEN) was 0.69-0.96; specificity (SPE) was 0.70-1.00; positive likelihood ratio (PLR) was 2.99-96.09; negative likelihood ratio (NLR) was 0.04-0.35; and diagnostic odds ratio (DOR) was 18.13-1250.71, respectively. Further, we analysed serum samples as a subgroup, and the pooled endpoints were as follows: pooled SEN was 0.89 (0.85-0.91); pooled SPE was 0.91 (0.88-0.93); pooled PLR was 12.35 (5.36-28.44); pooled NLR was 0.13 (0.09-0.20); and pooled DOR was 101.04 (39.57-258.04), respectively. SELDI-TOF-MS showed high accuracy in identifying lymphoma and could be a useful screening tool for diagnosing lymphoma patients.

Clinical instruments: reliability and validity critical appraisal

RATIONALE, AIM AND OBJECTIVES: There is a lack of health care practitioners using objective clinical tools with sound psychometric properties. There is also a need for researchers to improve their reporting of the validity and reliability results of these clinical tools. Therefore, to promote the use of valid and reliable tools or tests for clinical evaluation, this paper reports on the development of a critical appraisal tool to assess the psychometric properties of objective clinical tools.

METHOD

A five-step process was followed to develop the new critical appraisal tool: (1) preliminary conceptual decisions; (2) defining key concepts; (3) item generation; (4) assessment of face validity; and (5) formulation of the final tool.

RESULTS

The new critical appraisal tool consists of 13 items, of which five items relate to both validity and reliability studies, four items to validity studies only and four items to reliability studies. The 13 items could be scored as 'yes', 'no' or 'not applicable'.

CONCLUSION

This critical appraisal tool will aid both the health care practitioner to critically appraise the relevant literature and researchers to improve the quality of reporting of the validity and reliability of objective clinical tools.

The ability of clinical tests to diagnose stress fractures: a systematic review and meta-analysis

STUDY DESIGN

Systematic literature review and meta-analysis.

OBJECTIVES

To evaluate the diagnostic accuracy of clinical tests to identify stress fractures in the lower limb.

BACKGROUND

Stress fractures are a bone-related overuse injury primarily occurring in the lower limb and commonly affecting running athletes and military personnel. Physical examination procedures and clinical tests are suggested for diagnosing stress fractures; however, data on the diagnostic accuracy of these tests have not been investigated through a systematic review of the literature.

METHODS

A systematic review was conducted in 8 electronic databases to identify diagnostic accuracy studies, published between January 1950 and June 2011, that evaluated clinical tests against a radiological diagnosis of lower-limb stress fracture. Retrieved articles were evaluated using the Quality Assessment of Diagnostic Accuracy Studies tool, and a meta-analysis was performed where appropriate.

RESULTS

Nine articles investigating 2 clinical procedures, therapeutic ultrasound (n = 7) and tuning fork testing (n = 2), met the study inclusion criteria. Meta-analysis was used to statistically analyze the data extracted from the ultrasound articles and demonstrated a pooled sensitivity of 64% (95% confidence interval [CI]: 55%, 73%), specificity of 63% (95% CI: 54%, 71%), positive likelihood ratio of 2.1 (95% CI: 1.1, 3.5), and negative likelihood ratio of 0.3 (95% CI: 0.1, 0.9). Tuning fork test data could not be pooled; however, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio ranged from 35% to 92%, 19% to 83%, 0.6 to 3.0, and 0.4 to 1.6, respectively.

CONCLUSION

The results of this systematic review do not support the specific use of ultrasound or tuning forks as standalone diagnostic tests for lower-limb stress fractures. As the overall diagnostic accuracy of the tests investigated is not strong, based on the calculated likelihood ratios, it is recommended that radiological imaging should continue to be used for the confirmation and diagnosis of stress fractures of the lower limb.

LEVEL OF EVIDENCE

Diagnosis, level 1a-.J Orthop Sports Phys Ther 2012;42(9):760-771, Epub 19 July 2012. doi:10.2519/jospt.2012.4000.

Systematic review and meta-analysis of middle cerebral artery Doppler to predict perinatal wellbeing

OBJECTIVE

Identification of the fetus at risk of compromise is crucial to judicious allocation of monitoring resources and use of preventative treatment with the prospect of improving perinatal outcome. The accuracy of middle cerebral artery (MCA) Doppler for prediction of the fetus at risk of compromise of wellbeing is not known. The objective of this systematic review with bivariate meta-analysis was to evaluate the accuracy of middle cerebral artery Doppler for prediction of compromise of fetal/neonatal wellbeing.

STUDY DESIGN

Systematic review and bivariate meta-analysis with searches of Medline, Embase, Cochrane library, Medion (inception to October 2011), hand searching of journal and reference lists, contact with experts. Two reviewers independently selected articles in which the results of middle cerebral artery Doppler were associated with the occurrence of compromise of fetal/neonatal wellbeing. There were no language restrictions applied.

RESULTS

Thirty-five studies, testing 4025 fetuses, met the selection criteria. Data were extracted on study characteristics, quality and results to construct 2×2 tables. Likelihood ratios for positive and negative test results, sensitivity, specificity and their 95% confidence intervals were generated for the different indices and thresholds. Meta-analysis showed low predictive accuracy. For prediction of adverse perinatal outcome and perinatal mortality the results were positive likelihood ratios 2.77 (1.93, 3.96) and 1.36 (1.10, 1.67) and negative likelihood ratios 0.58 (0.48, 0.69) and 0.51 (0.29, 0.89) respectively.

CONCLUSION

Abnormal middle cerebral artery Doppler showed limited predictive accuracy for compromise of fetal/neonatal wellbeing. High quality primary research or individual patient data meta-analysis looking at this test in combination with other tests is required.

A systematic review of methods to diagnose oral dryness and salivary gland function

Background

The most advocated clinical method for diagnosing salivary dysfunction is to quantitate unstimulated and stimulated whole saliva (sialometry). Since there is an expected and wide variation in salivary flow rates among individuals, the assessment of dysfunction can be difficult. The aim of this systematic review is to evaluate the quality of the evidence for the efficacy of diagnostic methods used to identify oral dryness.

Methods

A literature search, with specific indexing terms and a hand search, was conducted for publications that described a method to diagnose oral dryness. The electronic databases of PubMed, Cochrane Library, and Web of Science were used as data sources. Four reviewers selected publications on the basis of predetermined inclusion and exclusion criteria. Data were extracted from the selected publications using a protocol. Original studies were interpreted with the aid of Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

Results

The database searches resulted in 224 titles and abstracts. Of these abstracts, 80 publications were judged to meet the inclusion criteria and read in full. A total of 18 original studies were judged relevant and interpreted for this review. In all studies, the results of the test method were compared to those of a reference method.

Based on the interpretation (with the aid of the QUADAS tool) it can be reported that the patient selection criteria were not clearly described and the test or reference methods were not described in sufficient detail for it to be reproduced. None of the included studies reported information on uninterpretable/intermediate results nor data on observer or instrument variation. Seven of the studies presented their results as a percentage of correct diagnoses.

Conclusions

The evidence for the efficacy of clinical methods to assess oral dryness is sparse and it can be stated that improved standards for the reporting of diagnostic accuracy are needed in order to assure the methodological quality of studies. There is need for effective diagnostic criteria and functional tests in order to detect those individuals with oral dryness who may require oral treatment, such as alleviation of discomfort and/or prevention of diseases.

Diagnostic value of EUS elastography in differentiation of benign and malignant solid pancreatic masses: a meta-analysis

BACKGROUND/AIMS

EUS elastography is a novel technique that can be used for distinguishing benign from malignant lymph nodes and focal pancreatic masses. However, the studies pertaining to EUS elastography for differential diagnosis of solid pancreatic masses have reported widely varied sensitivities and specificities. A meta-analysis of all relevant articles was performed to estimate the overall diagnostic accuracy of EUS elastography for differentiating benign and malignant solid pancreatic masses.

METHODS

The literatures were identified by searching in PubMed and Embase databases. Two reviewers independently extracted the information from the literatures for constructing 2 × 2 table. A random-effect model or a fixed-effect model was used to estimate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve (SROC) also was constructed. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity.

RESULTS

13 studies including a total of 1042 patients with solid pancreatic masses were selected for meta-analysis. The pooled sensitivity and specificity of EUS elastography for differentiating benign and malignant solid pancreatic masses were 95% (95% confidence interval [CI], 93%-96%), 69% (95% CI, 63%-75%), respectively. The area under SROC (AUC) was 0.8695. Two significant variables were associated with heterogeneity: color pattern and blinding.

CONCLUSION

As a less invasive modality, EUS elastography is a promising method for differentiating benign and malignant solid pancreatic masses with a high sensitivity, and it can prove to be a valuable supplement to EUS-FNA.

Does risk for ovarian malignancy algorithm excel human epididymis protein 4 and CA125 in predicting epithelial ovarian cancer: a meta-analysis

BACKGROUNDS

Risk for Ovarian Malignancy Algorithm (ROMA) and Human epididymis protein 4 (HE4) appear to be promising predictors for epithelial ovarian cancer (EOC), however, conflicting results exist in the diagnostic performance comparison among ROMA, HE4 and CA125.

METHODS

Remote databases (MEDLINE/PUBMED, EMBASE, Web of Science, Google Scholar, the Cochrane Library and ClinicalTrials.gov) and full texts bibliography were searched for relevant abstracts. All studies included were closely assessed with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2). EOC predictive value of ROMA was systematically evaluated, and comparison among the predictive performances of ROMA, HE4 and CA125 were conducted within the same population. Sensitivity, specificity, DOR (diagnostic odds ratio), LR ± (positive and negative likelihood ratio) and AUC (area under receiver operating characteristic-curve) were summarized with a bivariate model. Subgroup analysis and sensitivity analysis were used to explore the heterogeneity.

RESULTS

Data of 7792 tests were retrieved from 11 studies. The overall estimates of ROMA for EOC predicting were: sensitivity (0.89, 95% CI 0.84-0.93), specificity (0.83, 95% CI 0.77-0.88), and AUC (0.93, 95% CI 0.90-0.95). Comparison of EOC predictive value between HE4 and CA125 found, specificity: HE4 (0.93, 95% CI 0.87-0.96) > CA125 (0.84, 95% CI 0.76-0.90); AUC: CA125 (0.88, 95% CI 0.85-0.91) > HE4 (0.82, 95% CI 0.78-0.85). Comparison of OC predictive value between HE4 and CA125 found, AUC: CA125 (0.89, 95% CI 0.85-0.91) > HE4 (0.79, 95% CI 0.76-0.83). Comparison among the three tests for EOC prediction found, sensitivity: ROMA (0.86, 95%CI 0.81-0.91) > HE4 (0.80, 95% CI 0.73-0.85); specificity: HE4 (0.94, 95% CI 0.90-0.96) > ROMA (0.84, 95% CI 0.79-0.88) > CA125 (0.78, 95%CI 0.73-0.83).

CONCLUSIONS

ROMA is helpful for distinguishing epithelial ovarian cancer from benign pelvic mass. HE4 is not better than CA125 either for EOC or OC prediction. ROMA is promising predictors of epithelial ovarian cancer to replace CA125, but its utilization requires further exploration.

Correlation between Ki-67 immunohistochemistry and 18F-fluorothymidine uptake in patients with cancer: A systematic review and meta-analysis

BACKGROUND

Positron emission tomography (PET) imaging using the radiotracer 18F-Fluorothymidine (FLT) has been proposed as an imaging biomarker of tumour proliferation. If FLT-PET can be established as such it will provide a non-invasive, quantitative measurement of tumour proliferation across the entire tumour. Results from validation studies have so far been conflicting with some studies confirming a good correlation between FLT uptake and Ki-67 score and others presenting negative results.

METHODS

Firstly we performed a systematic review of published studies between 1998 and 2011 that explored the correlation between FLT uptake and Ki-67 score and examined possible variations in the methods used. Studies were eligible if they: (a) included patients with cancer, (b) investigated the correlation between Ki-67 measured by immunohistochemistry and FLT uptake measured with PET scanning, and (c) were published as a full paper in a peer-reviewed scientific journal. Secondly a meta-analysis of the correlation coefficient values reported from each study was performed. Correlation coefficient (r) values were extracted from each study and 95% confidence intervals (CIs) were calculated after applying Fisher's z transformation. For subgroup analysis, studies were classified by the index used to characterise Ki-67 expression (average or maximum expression), the nature of the sample (whole specimen or biopsy) and the cancer type.

FINDINGS

Twenty-seven studies were identified as eligible for the meta-analysis. In the studies we examined there were variations in aspects of the methods and reporting. The meta-analysis showed that given an appropriate study design the FLT/Ki-67 correlation is significant and independent of cancer type. Specifically subgroup analysis showed that FLT/Ki-67 correlation was high in studies measuring the Ki-67 average expression regardless of use of surgery or biopsy samples (r=0.70, 95% CI=0.43-0.86, p<0.001). Of the studies that measured Ki-67 maximum expression, only those that used the whole surgical specimen provided a significant r value (r=0.72, 95% CI=0.54-0.84, p<0.001). Studies that used biopsy samples for Ki-67 maximum measurements did not produce a significant r value (r=0.04, 95% CI=-0.18-0.26, p=0.71). In terms of the cancer type subgroup analysis there is sufficient data to support a strong FLT/Ki-67 correlation for brain, lung and breast cancer. No publication bias was detected.

INTERPRETATION

This systematic review and meta-analysis highlights the importance of the methods used in validation studies comparing FLT-PET imaging with the biomarker Ki-67. The correlation is significant and independent of cancer type provided a study design that uses Ki-67 average measurements, regardless of nature of sample, or whole surgical samples when measuring Ki-67 maximum expression. Sufficient data to support a strong correlation for brain, lung and breast cancer exist. However, larger, prospective studies with improved study design are warranted to validate these findings for the rest of the cancer types.

The diagnostic accuracy of magnetic resonance imaging and ultrasonography in gluteal tendon tears--a systematic review

Gluteal tendon tears are one of the many pathologies causing pain around the greater trochanter that are often labelled as trochanteric bursitis. We systematically reviewed the peer-reviewed literature to establish the accuracy of magnetic resonance imaging and ultrasonography in the diagnosis of gluteal tendon tears in patients with persistent lateral hip pain or Greater Trochanteric Pain Syndrome (GTPS). 7 studies met the inclusion criteria, comparing either imaging modality with a reference standard of surgical findings. Included studies were assessed for methodological quality using the QUADAS checklist. MRI had sensitivity of 33-100%, specificity of 92-100%, positive predictive value of 71-100% and negative predictive value of 50%. False-positives were common. High signal located superior to the trochanter had a stronger association with tears. Ultrasonography had a sensitivity of 79-100% and positive predictive value of 95-100%. The amount and quality of literature on the subject is limited and further well-designed studies are required to establish the optimum diagnostic strategy in this condition. Ultrasonography may prove to be the investigation of choice, despite requiring a skilled practitioner. The orthopaedic surgeon should liaise with an experienced musculoskeletal radiologist to best investigate and diagnose gluteal tendon tears in the clinical picture of GTPS.

Diagnostic accuracy of MRI for assessment of T category, lymph node metastases, and circumferential resection margin involvement in patients with rectal cancer: a systematic review and meta-analysis

BACKGROUND

Magnetic resonance imaging (MRI) is increasingly being used for rectal cancer staging. The purpose of this study was to determine the accuracy of phased array MRI for T category (T1-2 vs. T3-4), lymph node metastases, and circumferential resection margin (CRM) involvement in primary rectal cancer.

METHODS

Medline, Embase, and Cochrane databases were searched using combinations of keywords relating to rectal cancer and MRI. Reference lists of included articles were also searched by hand. Inclusion criteria were: (1) original article published January 2000-March 2011, (2) use of phased array coil MRI, (3) histopathology used as reference standard, and (4) raw data available to create 2×2 contingency tables. Patients who underwent preoperative long-course radiotherapy or chemoradiotherapy were excluded. Two reviewers independently extracted data. Sensitivity, specificity, and diagnostic odds ratio were estimated for each outcome using hierarchical summary receiver-operating characteristics and bivariate random effects modeling.

RESULTS

Twenty-one studies were included in the analysis. There was notable heterogeneity among studies. MRI specificity was significantly higher for CRM involvement [94%, 95% confidence interval (CI) 88-97] than for T category (75%, 95% CI 68-80) and lymph nodes (71%, 95% CI 59-81). There was no significant difference in sensitivity between the three elements as a result of wide overlapping CIs. Diagnostic odds ratio was significantly higher for CRM (56.1, 95% CI 15.3-205.8) than for lymph nodes (8.3, 95% CI 4.6-14.7) but did not differ significantly from T category (20.4, 95% CI 11.1-37.3).

CONCLUSIONS

MRI has good accuracy for both CRM and T category and should be considered for preoperative rectal cancer staging. In contrast, lymph node assessment is poor on MRI.

Golgi protein 73 versus alpha-fetoprotein as a biomarker for hepatocellular carcinoma: a diagnostic meta-analysis

Backgrounds

There have been conflicting reports about serum golgi protein 73 (GP73) as one of the most promising serum markers for the diagnosis of hepatocellular carcinoma (HCC). This study was to make a systematic review about the diagnostic accuracy of serum GP73 versus alpha-fetoprotein (AFP) for HCC.

Methods

After a systematic review of related studies, sensitivity, specificity and other measures about the accuracy of serum GP73 and AFP in the diagnosis of HCC were pooled using random-effects models. Summary receiver operating characteristic curve analysis was used to summarize the overall test performance.

Results

Eight studies were included in our meta-analysis. The summary estimates for serum GP73 and AFP in diagnosing HCC in the studies included were as follows: sensitivity, 76% (95% confidence interval (CI) 51-91%) vs. 70% (47-86%); specificity, 86% (95%CI 65-95%) vs. 89% (69-96%); diagnostic odds ratio (DOR), 18.59 (95%CI 5.33-64.91) vs. 18.00(9.41-34.46); and area under sROC, 0.88 (95%CI 0.77-0.99) vs. 0.86 (95%CI 0.84-0.87).

Conclusions

The current evidence indicates that serum GP73 has a comparable accuracy to AFP for the diagnosis of HCC, while the value of serum GP73 in combination with AFP for HCC detection deserves further investigation.

Diagnostic accuracy of clinical characteristics for identifying CT abnormality after minor brain injury: a systematic review and meta-analysis

Clinical features can be used to identify which patients with minor brain injury need CT scanning. A systematic review and meta-analysis was undertaken to estimate the value of these characteristics for diagnosing intracranial injury (including the need for neurosurgery) in adults, children, and infants. Potentially relevant studies were identified through electronic searches of several key databases, including MEDLINE, from inception to March 2010. Cohort studies of patients with minor brain injury (Glasgow Coma Score [GCS], 13-15) were selected if they reported data on the diagnostic accuracy of individual clinical characteristics for intracranial or neurosurgical injury. Where applicable, meta-analysis was used to estimate pooled sensitivity, specificity and likelihood ratios. Data were extracted from 71 studies (with cohort sizes ranging from 39 to 31,694 patients). Depressed or basal skull fracture were the most useful clinical characteristics for the prediction of intracranial injury in both adults and children (positive likelihood ratio [PLR], >10). Other useful characteristics included focal neurological deficit, post-traumatic seizure (PLR >5), persistent vomiting, and coagulopathy (PLR 2 to 5). Characteristics that had limited diagnostic value included loss of consciousness and headache in adults and scalp hematoma and scalp laceration in children. Limited studies were undertaken in children and only a few studies reported data for neurosurgical injuries. In conclusion, this review identifies clinical characteristics that indicate increased risk of intracranial injury and the need for CT scanning. Other characteristics, such as headache in adults and scalp laceration of hematoma in children, do not reliably indicate increased risk.

Magnetic resonance imaging for diagnosing lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review

PURPOSE

In about 5% of all cases LBP is associated with serious underlying pathology requiring diagnostic confirmation and directed treatment. Magnetic resonance imaging (MRI) is often used for this diagnostic purpose yet its role remains controversial. Consequently, this review aimed to summarize the available evidence on the diagnostic accuracy of MRI for identifying lumbar spinal pathology in adult low back pain (LPB) or sciatica patients.

METHODS

MEDLINE, EMBASE and CINAHL were searched (until December 2009) for observational studies assessing the diagnostic accuracy of MRI compared to a reference test for the identification of lumbar spinal pathology. Two reviewers independently selected studies for inclusion, extracted data and assessed methodological quality. Pooled summary estimates of sensitivity and specificity with 95% confidence intervals were calculated for homogenous subsets of studies.

RESULTS

Eight studies were included in this review. Strata were defined for separate pathologies i.e. lumbar disc herniation (HNP) and spinal stenosis. Five studies comparing MRI to findings at the surgery for identifying HNP were included in a meta-analysis. Pooled analysis resulted in a summary estimate of sensitivity of 75% (95% CI 65-83%) and specificity of 77% (95% CI 61-88%). For spinal stenosis pooling was not possible.

CONCLUSIONS

The results suggest that a considerable proportion of patients may be classified incorrectly by MRI for HNP and spinal stenosis. However, the evidence for the diagnostic accuracy of MRI found by this review is not conclusive, since the results could be distorted due to the limited number of studies and large heterogeneity.

Hand-held dynamometry correlation with the gold standard isokinetic dynamometry: a systematic review

OBJECTIVE

To examine the current evidence regarding the reliability and validity of hand-held dynamometry for assessment of muscle strength in the clinical setting.

DATA SOURCES

A search was conducted of the following databases: Cochrane, MEDLINE, PubMed, PEDro, OTseeker, Index to Chiropractic Literature (ICL), and MANTIS, from inception until January 29, 2010.

STUDY SELECTION

The MeSH subject heading "muscle strength dynamometer" was searched, in isolation and in combination with the text word phrases "hand-held dynamometer" and "isokinetic." Four hundred fifty-four different studies met this search and were reviewed for possible inclusion.

DATA EXTRACTION

Two independent reviewers assessed the quality of the included manuscripts. The PEDro data collection system was used in conjunction with the Cochrane Diagnostic Test Accuracy Description. A third reviewer was used when there was disagreement between the primary reviewers.

DATA SYNTHESIS

Seventeen manuscripts met the inclusion criteria for this review, with a total of 19 studies (2 of the manuscripts involved 2 separate studies) that compared hand-held dynamometry with an identified reference standard (isokinetic muscle strength testing). The results demonstrated minimal differences between hand-held dynamometry and isokinetic testing.

CONCLUSIONS

Considering hand-held dynamometry's ease of use, portability, cost, and compact size, compared with isokinetic devices this instrument can be regarded as a reliable and valid instrument for muscle strength assessment in a clinical setting.

Computed tomography for the diagnosis of lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review

Aim

In low back pain if serious pathology is suspected diagnostic imaging could be performed. One of the imaging techniques available for this purpose is computed tomography (CT), however, insight in the diagnostic performance of CT is unclear.

Method

Diagnostic systematic review. Studies assessing the diagnostic accuracy of CT in adult patients suggested having low back pain caused by specific pathology were selected. Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias. Pooled summary estimates of sensitivity and specificity with 95% CI were calculated.

Results

Seven studies were included, all describing the diagnostic accuracy of CT in identifying lumbar disc herniation. Six studies used surgical findings as the reference standard and were considered sufficiently homogenous to carry out a meta-analysis. The pooled summary estimate of sensitivity was 77.4% and specificity was 73.7%.

Conclusions

We found no studies evaluating the accuracy of CT for pathologies such as vertebral cancer, infection and fractures and this remains unclear. Our results should be interpreted with some caution. Sensitivity and specificity, regarding the detection of lumbar disc herniation, showed that a substantial part of the patients is still classified as false-negative and false-positive. In future, the diagnostic performance of CT must be assessed in high quality prospective cohort studies with an unselected population of patients with low back pain.

Identification of developmental-behavioral problems in primary care: a systematic review

CONTEXT

Recent mandates and recommendations for formal screening programs are based on the claim that pediatric care providers underidentify children with developmental-behavioral disorders, yet the research to support this claim has not been systematically reviewed.

OBJECTIVE

To review research literature for studies regarding pediatric primary care providers' identification of developmental-behavioral problems in children.

METHODS

On the basis of a Medline search conducted on September 22, 2010, using relevant key words, we identified 539 articles for review. We included studies that (1) were conducted in the United States, (2) were published in peer-reviewed journals, (3) included data that addressed pediatric care providers' identification of developmental-behavioral problems in individual patients, (4) included an independent assessment of patients' developmental-behavioral problems, such as diagnostic interviews or validated screening instruments, and (5) reported data sufficient to calculate sensitivity and specificity. Studies were not limited by sample size. Eleven articles met these criteria. We used Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria to evaluate study quality. Although the studies were similar in many ways, heterogeneous methodology precluded a meta-analysis.

RESULTS

Sensitivities for pediatric care providers ranged from 14% to 54%, and specificities ranged from 69% to 100%. The authors of 1 outlier study reported a sensitivity of 85% and a specificity of 61%.

CONCLUSIONS

Pediatricians are often the first point of entry into developmental and mental health systems. Knowing their accuracy in identifying children with developmental-behavioral disabilities is essential for implementing optimal evaluation programs and achieving timely identification. Moreover, these statistics are important to consider when planning large-scale screening programs.

Creation and Critique of Studies of Diagnostic Accuracy: Use of the STARD and QUADAS Methodological Quality Assessment Tools

Clinical special tests are a mainstay of orthopaedic diagnosis. Within the context of the evidence-based practice paradigm, data on the diagnostic accuracy of these special tests are frequently used in the decision-making process when determining the diagnosis, prognosis, and selection of appropriate intervention strategies. However, the reported diagnostic utility of these tests is significantly affected by study methodology of diagnostic accuracy studies. Methodological shortcomings can influence the outcome of such studies, and this in turn will affect the clinician's interpretation of diagnostic findings. The methodological issues associated with studies investigating the diagnostic utility of clinical tests have mandated the development of the STARD (Standards for Reporting of Diagnostic Accuracy) and QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criterion lists. The purpose of this paper is to outline the STARD and QUADAS criterion lists and to discuss how these methodological quality assessment tools can assist the clinician in ascertaining clinically useful information from a diagnostic accuracy study.

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis

STUDY OBJECTIVE

To determine if the use of ultrasound guidance (vs non-ultrasound techniques) improves the success rate of nerve blocks.

DESIGN

Meta-analysis of randomized controlled trials (RCTs) in the published literature.

SETTING

University medical center.

MEASUREMENTS

16 RCTs of patients undergoing elective surgical procedures were studied. Patients underwent ultrasound-guided or non-ultrasound techniques (nerve stimulation, surface landmark) for peripheral nerve blocks. Success rates were measured.

MAIN RESULTS

Ultrasound guidance (vs all non-ultrasound techniques) was associated with a significant increase in the success rate of nerve blocks [relative risk (RR) = 1.11 (95% confidence interval [CI]: 1.06 to 1.17, P < 0.0001]). When compared with nerve stimulator techniques only, ultrasound guidance was still associated with an increase in the success rate (RR = 1.11 [95% CI: 1.05 to 1.17, P = 0.0001]). For specific blocks, ultrasound guidance (vs all non-ultrasound) was associated with a significant increase in successful brachial plexus (all) nerve blocks (RR = 1.11 [95% CI: 1.05 to 1.20, P = 0.0001]), sciatic popliteal nerve block (RR = 1.22 [95% CI: 1.08 to 1.39, P = 0.002]) and brachial plexus axillary nerve block (RR = 1.13 [95% CI: 1.00 to 1.26, P = 0.05]) but not brachial plexus infraclavicular nerve block (RR = 1.25 [95% CI: 0.88 to 1.76, P = 0.22]).

CONCLUSIONS

Ultrasound-guided peripheral nerve block is associated with an increased overall success rate when compared with nerve stimulation or other methods. Ultrasound-guided techniques also increase the success rate of some specific blocks.

A new instrument for assessing the quality of studies on prevalence

There are numerous scientific articles of studies on the prevalence of disorders with non-standardised examination and diagnostic protocols. Because their quality is heterogeneous, a new instrument has been developed for the assessment of such studies. The new instrument is based mainly on statistical criteria. The points assigned for each of the main criteria according to the information gained from each paper are summed up to form a Total Quality Score (TQS). The interrater reliability of the instrument was tested by employing Kappa and Interrater Correlation Coefficient (ICC) statistics. The latter was assessed on the results of three independent investigators. The new quality instrument appeared to be easy to use, and the instructions were comprehensible. The ICC((2,1)) for the TQS ranged between 0.94 and 1.00 indicating almost perfect agreement between the investigators. The reliability of the new instrument enables its use for scientific review purposes. In this way, its validity will also be tested. The instrument could be adopted for assessment of scientific articles of studies on the prevalence of disorders in many, similar, scientific areas.

Scales for the identification of adults with attention deficit hyperactivity disorder (ADHD): a systematic review

Attention deficit hyperactivity disorder (ADHD) is prevalent in the adult population. The associated co-morbidities and impairments can be relieved with treatment. Therefore, several rating scales have been developed to identify adults with ADHD who may benefit from treatment. No systematic review has yet sought to evaluate these scales in more detail. The present systematic review was undertaken to describe the properties, including psychometric statistics, of the currently available adult ADHD rating scales and their scoring methods, along with the procedure for development. Descriptive synthesis of the data is presented and study quality has been assessed by an objective quality assessment tool. The properties of each scale are discussed to make judgements about their validity and usefulness. The literature search retrieved 35 validation studies of adult ADHD rating scales and 14 separate scales were identified. The majority of studies were of poor quality and reported insufficient detail. Of the 14 scales, the Conners' Adult ADHD Rating scale and the Wender Utah Rating Scale (short version) had more robust psychometric statistics and content validity. More research into these scales, with good quality studies, is needed to confirm the findings of this review. Future studies of ADHD rating scales should be reported in more detail so that further reviews have more support for their findings.

Prognostic models for the early care of trauma patients: a systematic review

BACKGROUND

Early identification of major trauma may contribute to timely emergency care and rapid transport to an appropriate health-care facility. Several prognostic trauma models have been developed to improve early clinical decision-making.

METHODS

We systematically reviewed models for the early care of trauma patients that included 2 or more predictors obtained from the evaluation of an adult trauma victim, investigated their quality and described their characteristics.

RESULTS

We screened 4,939 records for eligibility and included 5 studies that derivate 5 prognostic models and 9 studies that validate one or more of these models in external populations. All prognostic models intended to change clinical practice, but none were tested in a randomised clinical trial. The variables and outcomes were valid, but only one model was derived in a low-income population. Systolic blood pressure and level of consciousness were applied as predictors in all models.

CONCLUSIONS

The general impression is that the models perform well in predicting survival. However, there are many areas for improvement, including model development, handling of missing data, analysis of continuous measures, impact and practicality analysis.

Novel biomarkers for the prediction of the spontaneous preterm birth phenotype: a systematic review and meta-analysis

BACKGROUND

Being able to predict preterm birth is important, as it may allow a high-risk population to be selected for future interventional studies and help in understanding the pathways that lead to preterm birth.

OBJECTIVE

To investigate the accuracy of novel biomarkers to predict spontaneous preterm birth in women with singleton pregnancies and no symptoms of preterm labour.

SEARCH STRATEGY

Electronic searches in PubMed, Embase, Cinahl, Lilacs, and Medion, references of retrieved articles, and conference proceedings. No language restrictions were applied.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of biomarkers proposed in the last decade to predict spontaneous preterm birth in asymptomatic women. We excluded studies in which biomarkers were evaluated in women with preterm labour.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data on study characteristics, quality, and accuracy. Data were arranged in 2 × 2 contingency tables and synthesised separately for spontaneous preterm birth before 32, 34, and 37 weeks of gestation. We used bivariate meta-analysis to estimate pooled sensitivities and specificities, and calculated likelihood ratios (LRs).

MAIN RESULTS

A total of 72 studies, including 89,786 women and evaluating 30 novel biomarkers, met the inclusion criteria. Only three biomarkers (proteome profile and prolactin in cervicovaginal fluid, and matrix metalloproteinase-8 in amniotic fluid) had positive LRs > 10. However, each of these biomarkers was evaluated in only one small study. Four biomarkers had a moderate predictive accuracy (interleukin-6 and angiogenin, in amniotic fluid; human chorionic gonadotrophin and phosphorylated insulin-like growth factor binding protein-1, in cervicovaginal fluid). The remaining biomarkers had low predictive accuracies.

CONCLUSIONS

None of the biomarkers evaluated in this review meet the criteria to be considered a clinically useful test to predict spontaneous preterm birth. Further large, prospective cohort studies are needed to evaluate promising biomarkers such as a proteome profile in cervicovaginal fluid.

Clinical tests to diagnose lumbar segmental instability: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To evaluate the diagnostic accuracy of clinical tests used to diagnose patients with structural lumbar segmental instability (LSI).

BACKGROUND

Patients with structural LSI represent an important, identifiable subgrouping of individuals with low back pain. Numerous clinical tests have been proposed to diagnose structural LSI; however, data on the diagnostic accuracy of these tests have not yet been evaluated through a systematic review of the literature.

METHODS

A systematic review was conducted in 6 electronic databases for diagnostic accuracy studies, published between January 1950 and March 2010, that evaluated clinical tests against radiological diagnosis of structural LSI. The diagnostic accuracy of the clinical tests from the retrieved articles was independently evaluated, reviewed, and quality scored using the QUADAS tool.

RESULTS

Four articles and a total of 11 clinical tests used in the diagnosis of structural LSI met the study inclusion criteria. The majority of tests had high specificity but low sensitivity, with positive likelihood ratios ranging from very small to moderate. QUADAS scores ranged from 16 to 25 out of a possible 26. The passive lumbar extension test was the most accurate clinical test, with high sensitivity (84%), specificity (90%), and a positive likelihood ratio of 8.8 (95% CI: 4.5, 17.3), indicating that this clinical test may be useful in the differential diagnosis of structural LSI.

CONCLUSION

This systematic review found that the majority of clinical tests routinely employed to diagnose structural LSI demonstrated only limited ability to do so. The results do, however, indicate that the passive lumbar extension test may be useful in orthopaedic clinical practice to diagnose structural LSI. Additional research is required to further validate its use for diagnosing structural LSI in all populations of those with low back pain.

LEVEL OF EVIDENCE

Diagnosis, level 2a.

Physical activity and low back pain: a systematic review of recent literature

The objective of the study is to systematically evaluate the available evidence on the association between physical activity (i.e. occupational load and non-occupational physical activities) and low back pain (LBP). A systematic approach was used to explore the literature between 1999 and 2009. Studies were selected for inclusion following a comprehensive search of Medline, Embase and CINAHL. The methodological quality of each study was assessed. Studies were considered to be of 'high quality' if they met the cut-off criterion of 60% of the maximum available quality score. Thirty-six cohort or case-control studies were retrieved. Heavy workload and the accumulation of loads or frequency of lifts were moderate to strong risk factors for LBP. Strong associations were found for flexed, rotated and the awkward positions of the lumbar spine. Inconsistent results were found for leisure time physical activities, sports and physical exercise. Studies focusing on daily habitual physical activities (e.g. domestic activities and commuting) in association with LBP are lacking. In conclusion, the occurrence of LBP is related to the nature and intensity of the physical activities undertaken. However, physical activities can be subdivided into separate types and intensities and the ultimate physical load is the sum of all these activities. This makes it difficult to designate one particular activity as the cause of LBP.

Meta-analysis of heterogeneous clinical trials: an empirical example

Meta-analysis of heterogeneous clinical trials is currently sub-optimal. This is because there has been no improvement in the method of weighted averaging for such studies since the DL method in 1986. This article presents the argument for the use of situation specific weights to integrate results from such trials. An empirical example is given with data from a meta-analysis done 10 years earlier. Previously reported data on 21 studies that looked at the effect of working conditions on preterm births were re-analyzed. Several methods were used to estimate the overall effect sizes. Study specific scores were included in the weighting process when combining studies and it was shown that this model not only was more conservative than the model of DL but also retains the legitimacy of the pooled effect size. The inclusion of appropriate study specific scores in an appropriate meta-analysis model permits the quantification of the variation between studies based on something tangible as opposed to the random adjustments made by the random effects model to the pooled effect size. It is important that such differences are recognized by the wider research community so that meta-analyses remain a valid tool for synthesizing research.

Cervicovaginal fetal fibronectin for the prediction of spontaneous preterm birth in multiple pregnancies: a systematic review and meta-analysis

OBJECTIVE

To investigate the accuracy of cervicovaginal fetal fibronectin in predicting preterm birth in women with multiple pregnancies.

METHODS

Systematic review and meta-analysis of predictive test accuracy. Cohort or cross-sectional studies were identified through searches in databases, reference lists, proceedings, and reviews. Study selection, quality assessment, and data extraction were performed. We constructed summary receiver operating characteristic curves and calculated pooled sensitivities and specificities using a bivariate, random-effects meta-regression model. We also calculated summary likelihood ratios and post-test probabilities of preterm birth.

RESULTS

Fifteen studies (11 in asymptomatic women and 4 in women with symptoms of preterm labor) involving 1221 women with multiple pregnancies were included. Among asymptomatic women with multiple or twin pregnancies, the pooled sensitivities, specificities, and positive and negative likelihood ratios for predicting preterm birth before 32, 34, and 37 weeks' gestation ranged from 33% to 45%, 80% to 94%, 2.0 to 5.5, and 0.68 to 0.76, respectively. Among women with twin pregnancies and threatened preterm labor, the test was most accurate in predicting spontaneous preterm birth within 7 days of testing (pooled sensitivity, specificity, and positive and negative likelihood ratios of 85%, 78%, 3.9, and 0.20, respectively).

CONCLUSIONS

Cervicovaginal fetal fibronectin provides moderate to minimal prediction of preterm birth in women with multiple pregnancies. The test is most accurate in predicting spontaneous preterm birth within 7 days of testing in women with twin pregnancies and threatened preterm labor.

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

Background

Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.

Methods

A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.

Results

Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.

Conclusions

Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.

Accuracy of diagnostic ultrasound in patients with suspected subacromial disorders: a systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of ultrasound for detecting subacromial disorders in patients presenting in primary and secondary care settings.

DATA SOURCES

Medline and Embase were searched on June 9, 2010. In addition, the reference list of 1 systematic review and all included articles were searched to identify relevant studies.

STUDY SELECTION

Two reviewers independently selected the articles evaluating the accuracy of ultrasound for detecting subacromial disorders from the title and abstracts retrieved by the literature search. Selection criteria were ultrasound frequency greater than or equal to 7.5MHz as index test, surgery, magnetic resonance imaging and/or radiography as reference standards, and subacromial disorders as target conditions.

DATA EXTRACTION

Two reviewers independently extracted the data on study characteristics and results to construct 2 by 2 tables and performed a methodologic quality assessment.

DATA SYNTHESIS

Twenty-three studies were included: 22 reported on full-thickness rotator cuff tears, 15 on partial-thickness tears, 3 on subacromial bursitis, 2 on tendinopathy, and 2 on calcifying tendonitis, respectively. For full-thickness tears, pooled sensitivity of ultrasound was .95 (95% confidence interval, .90-.97), and specificity .96 (.93-.98). For partial-thickness tears, pooled sensitivity was .72 (.58-.83), and specificity .93 (.89-.96). Statistical pooling was not possible for the other disorders. For subacromial bursitis, sensitivity ranged from .79 to .81, and specificity from .94 to .98. For tendinopathy, sensitivity ranged from .67 to .93, specificity from .88 to 1.00. Sensitivity for calcifying tendonitis was 1.00 in both studies, with specificity ranging from .85 to .98.

CONCLUSIONS

We strongly recommend ultrasound in patients for whom conservative treatment fails, to rule in or out full-thickness tears, to rule in partial-thickness tears, and to a lesser extent to diagnose tendinopathy, subacromial bursitis, and calcifying tendonitis. These results can help physicians tailor treatment.

Center of pressure excursion as a measure of balance performance in patients with non-specific low back pain compared to healthy controls: a systematic review of the literature

Over the past 20 years, the center of pressure (COP) has been commonly used as an index of postural stability in standing. While many studies investigated COP excursions in low back pain patients and healthy individuals, no comprehensive analysis of the reported differences in postural sway pattern exists. Six online databases were systematically searched followed by a manual search of the retrieved papers. The selection criteria comprised papers comparing COP measures derived from bipedal static task conditions on a force-plate of non-specific low back pain (NSLBP) sufferers to those of healthy controls. Sixteen papers met the inclusion criteria. Heterogeneity in study designs prevented pooling of the data so only a qualitative data analysis was conducted. The majority of the papers (14/16, 88%) concluded that NSLBP patients have increased COP mean velocity and overall excursion as compared to healthy individuals. This was statistically significant in the majority of studies (11/14, 79%). An increased sway in anteroposterior direction was also observed in NSLBP patients. Patients with NSLBP exhibit greater postural instability than healthy controls, signified by greater COP excursions and a higher mean velocity. While the decreased postural stability in NSLBP sufferers further appears to be associated with the presence of pain, it seems unrelated to the exact location and pain duration. No correlation between the pain intensity and the magnitude of COP excursions could be identified.

Diagnostic utility of clinical tests for spinal dysfunction

The purpose of this study was to outline the clinical tests that exhibit the highest diagnostic utility for the spine. Using a sensitive search strategy but highly restrictive inclusion criteria based on assessment of quality and reduction of bias, we identified 16 well constructed diagnostic accuracy studies of the spine. Within the 16 studies, 14 clinical tests were identified, and of the 14, four cervical tests and two lumbar tests were considered good screening tools whereas one cervical test and five lumbar tests were considered good tools for confirmatory diagnosis. A significant number of clinical tests were not included in our final tally secondary to poor study designs and the risks associated with inflated findings and bias. High quality diagnostic accuracy studies for the spine are necessary to improve clinicians' abilities to rule out sinister disorders.

Transvaginal sonographic cervical length for the prediction of spontaneous preterm birth in twin pregnancies: a systematic review and metaanalysis

OBJECTIVE

To assess the accuracy of transvaginal sonographic cervical length (CL) in predicting spontaneous preterm birth in women with twin pregnancies.

STUDY DESIGN

Systematic review and metaanalysis of predictive test accuracy.

RESULTS

Twenty-one studies (16 in asymptomatic women and 5 in symptomatic women) with a total of 3523 women met the inclusion criteria. Among asymptomatic women, a CL

CONCLUSION

Transvaginal sonographic CL at 20-24 weeks' gestation is a good predictor of spontaneous preterm birth in asymptomatic women with twin pregnancies.

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Key Words

• cervical length
• preterm birth
• prediction
• metaanalysis
• systematic review

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MESH Headings

• Cervix Uteri/anatomy & histology
• Cervix Uteri/diagnostic imaging
• Female
• Gestational Age
• Humans
• Incidence
• Infant, Newborn
• Predictive Value of Tests
• Pregnancy
• Pregnancy Outcome
• Pregnancy, Multiple
• Premature Birth/diagnostic imaging
• Premature Birth/epidemiology
• Risk Assessment
• Twins
• Ultrasonography, Prenatal

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Grants

• ZIA HD002401 Intramural NIH HHS
• ZIA HD002401-18 Intramural NIH HHS

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Affiliation(s)

Agustín Conde-Agudelo Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health/Department of Health and Human Services, Bethesda, MD, USA
Roberto Romero
Sonia S Hassan
Lami Yeo

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Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis

OBJECTIVE

To evaluate whether including a test for faecal calprotectin, a sensitive marker of intestinal inflammation, in the investigation of suspected inflammatory bowel disease reduces the number of unnecessary endoscopic procedures.

DESIGN

Meta-analysis of diagnostic accuracy studies.

DATA SOURCES

Studies published in Medline and Embase up to October 2009. Interventions reviewed Measurement of faecal calprotectin level (index test) compared with endoscopy and histopathology of segmental biopsy samples (reference standard). Inclusion criteria Studies that had collected data prospectively in patients with suspected inflammatory bowel disease and allowed for construction of a two by two table. For each study, sensitivity and specificity of faecal calprotectin were analysed as bivariate data to account for a possible negative correlation within studies.

RESULTS

13 studies were included: six in adults (n=670), seven in children and teenagers (n=371). Inflammatory bowel disease was confirmed by endoscopy in 32% (n=215) of the adults and 61% (n=226) of the children and teenagers. In the studies of adults, the pooled sensitivity and pooled specificity of calprotectin was 0.93 (95% confidence interval 0.85 to 0.97) and 0.96 (0.79 to 0.99) and in the studies of children and teenagers was 0.92 (0.84 to 0.96) and 0.76 (0.62 to 0.86). The lower specificity in the studies of children and teenagers was significantly different from that in the studies of adults (P=0.048). Screening by measuring faecal calprotectin levels would result in a 67% reduction in the number of adults requiring endoscopy. Three of 33 adults who undergo endoscopy will not have inflammatory bowel disease but may have a different condition for which endoscopy is inevitable. The downside of this screening strategy is delayed diagnosis in 6% of adults because of a false negative test result. In the population of children and teenagers, 65 instead of 100 would undergo endoscopy. Nine of them will not have inflammatory bowel disease, and diagnosis will be delayed in 8% of the affected children.

CONCLUSION

Testing for faecal calprotectin is a useful screening tool for identifying patients who are most likely to need endoscopy for suspected inflammatory bowel disease. The discriminative power to safely exclude inflammatory bowel disease was significantly better in studies of adults than in studies of children.

Guidelines for diagnostic tests and diagnostic accuracy in surgical research

OBJECTIVE

This is a guideline review of the application of diagnostic tests and diagnostic accuracy in surgical research.

SUMMARY BACKGROUND DATA

There is an increasing use of diagnostic tests in surgery, and an understanding of the accuracy for each test is important for surgeons.

METHODS

This methodological review outlines the basic concepts of diagnostic test accuracy, including sensitivity, specificity, diagnostic odds ratio, likelihood ratios, and predictive values. Sources of bias in diagnostic accuracy studies are explained in simplified terms. The graphical methods used to present diagnostic accuracy are demonstrated. Study quality issues are outlined using published guidelines. Finally, the principles of diagnostic meta-analysis, including more advanced approaches such as bivariate and hierarchical summary receiver operating characteristic methods are explained.

CONCLUSION

In the era of evidence-based surgery, the ability to understand and interpret the fundamental principles of diagnostic accuracy literature is vital to improve patient care and reduce the confusion in clinical practice over the most appropriate diagnostic test.

Methodological deficits in diagnostic research using '-omics' technologies: evaluation of the QUADOMICS tool and quality of recently published studies

Background

QUADOMICS is an adaptation of QUADAS (a quality assessment tool for use in systematic reviews of diagnostic accuracy studies), which takes into account the particular challenges presented by ‘-omics’ based technologies. Our primary objective was to evaluate the applicability and consistency of QUADOMICS. Subsequently we evaluated and describe the methodological quality of a sample of recently published studies using the tool.

Methodology/Principal Findings

45‘-omics’- based diagnostic studies were identified by systematic search of Pubmed using suitable MeSH terms (“Genomics”, “Sensitivity and specificity”, “Diagnosis”). Three investigators independently assessed the quality of the articles using QUADOMICS and met to compare observations and generate a consensus. Consistency and applicability was assessed by comparing each reviewer's original rating with the consensus. Methodological quality was described using the consensus rating. Agreement was above 80% for all three reviewers. Four items presented difficulties with application, mostly due to the lack of a clearly defined gold standard. Methodological quality of our sample was poor; studies met roughly half of the applied criteria (mean ± sd, 54.7±18.4%). Few studies were carried out in a population that mirrored the clinical situation in which the test would be used in practice, (6, 13.3%); none described patient recruitment sufficiently; and less than half described clinical and physiological factors that might influence the biomarker profile (20, 44.4%).

Conclusions

The QUADOMICS tool can consistently be applied to diagnostic ‘-omics’ studies presently published in biomedical journals. A substantial proportion of reports in this research field fail to address design issues that are fundamental to make inferences relevant for patient care.

Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: a meta-analysis

BACKGROUND

We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection.

METHODS

MEDLINE, Cochrane library, and BioMed Central database searches were performed until April 2009 for original articles. Inclusion criteria were (1) 64-MDCT was used as a diagnostic test for ISR, with >50% diameter stenosis selected as the cut-off criterion for significant ISR, using invasive coronary angiography and quantitative coronary angiography as the standard of reference; (2) absolute numbers of true positive, false positive, true negative, and false negative results could be derived. Standard meta-analytic methods were applied.

RESULTS

Nine studies with a total of 598 patients with 978 stents included were considered eligible. On average, 9% of stents were unassessable (range 0-42%). Accuracy tests with 95% confidence intervals (CIs) comparing 64-MDCT vs invasive coronary angiography showed that pooled sensitivity, specificity, positive and negative likelihood ratio (random effect model) values were: 86% (95% CI 80-91%), 93% (95% CI 91-95%), 12.32 (95% CI 7.26-20.92), 0.18 (95% CI 0.12-0.28) for binary ISR detection. The symmetric area under the curve value was 0.94, indicating good agreement between 64-MDCT and invasive coronary angiography.

CONCLUSIONS

64-MDCT has a good diagnostic accuracy for ISR detection with a particularly high negative predictive value. However, still a relatively large proportion of stents remains uninterpretable. Accordingly, only in selected patients, 64-MDCT may serve as a potential alternative noninvasive method to rule out ISR.

Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis

OBJECTIVE

To evaluate the association between umbilical cord pH at birth and long term outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline (1966-August 2008), Embase (1980-August 2008), the Cochrane Library (2008 issue 8), and Medion, without language restrictions; reference lists of selected articles; and contact with authors.

STUDY SELECTION

Studies in which cord pH at birth was compared with any neonatal or long term outcome. Cohort and case-control designs were included.

RESULTS

51 articles totalling 481 753 infants met the selection criteria. Studies varied in design, quality, outcome definition, and results. Meta-analysis carried out within predefined groups showed that low arterial cord pH was significantly associated with neonatal mortality (odds ratio 16.9, 95% confidence interval 9.7 to 29.5, I(2)=0%), hypoxic ischaemic encephalopathy (13.8, 6.6 to 28.9, I(2)=0%), intraventricular haemorrhage or periventricular leucomalacia (2.9, 2.1 to 4.1, I(2)=0%), and cerebral palsy (2.3, 1.3 to 4.2, I(2)=0%).

CONCLUSIONS

Low arterial cord pH showed strong, consistent, and temporal associations with clinically important neonatal outcomes that are biologically plausible. These data can be used to inform clinical management and justify the use of arterial cord pH as an important outcome measure alongside neonatal morbidity and mortality in obstetric trials.

Association between framing of the research question using the PICOT format and reporting quality of randomized controlled trials

Background

Experts recommend formulating a structured research question to guide the research design. However, the basis for this recommendation has not been formally evaluated. The aim of this study was to examine if a structured research question using the PICOT (Population, Intervention, Comparator, Outcome, Time-frame) format is associated with a better reporting quality of randomized controlled trials (RCTs).

Methods

We evaluated 89 RCTs reports published in three endocrinology journals in 2005 and 2006, the quality of reporting of which was assessed in a previous study. We examined whether the reports stated each of the five elements of a structured research question: population, intervention, comparator, outcome and time-frame. A PICOT score was created with a possible score between 0 and 5. Outcomes were: 1) a 14-point overall reporting quality score (OQS) based on the Consolidated Standards for Reporting Trials; and 2) a 3-point key score (KS), based on allocation concealment, blinding and use of intention-to-treat analysis. We conducted multivariable regression analyses using generalized estimating equations to determine if a higher PICOT score or the use of a structured research question were independently associated with a better reporting quality. Journal of publication, funding source and sample size were identified as factors associated with OQS in our previous report on this dataset, and therefore included in the model.

Results

A higher PICOT score was independently associated with OQS (incidence rate ratio (IRR) = 1.021, 95% CI: 1.012 to 1.029) and KS (IRR = 1.142, 95% CI: 1.079 to 1.210). A structured research question was present in 33.7% of the reports and it was associated with a better OQS (IRR = 1.095, 95% CI 1.059-1.132) and KS (IRR = 1.530, 95% CI 1.311-1.786).

Conclusions

Better framing of the research question using the PICOT format is independently associated with better overall reporting quality - although the effect is small - and better reporting of key methodologies.

Cerebral magnetic resonance biomarkers in neonatal encephalopathy: a meta-analysis

OBJECTIVE

Accurate prediction of neurodevelopmental outcome in neonatal encephalopathy (NE) is important for clinical management and to evaluate neuroprotective therapies. We undertook a meta-analysis of the prognostic accuracy of cerebral magnetic resonance (MR) biomarkers in infants with neonatal encephalopathy.

METHODS

We reviewed all studies that compared an MR biomarker performed during the neonatal period with neurodevelopmental outcome at > or =1 year. We followed standard methods recommended by the Cochrane Diagnostic Accuracy Method group and used a random-effects model for meta-analysis. Summary receiver operating characteristic curves and forest plots of each MR biomarker were calculated. chi(2) tests examined heterogeneity.

RESULTS

Thirty-two studies (860 infants with NE) were included in the meta-analysis. For predicting adverse outcome, conventional MRI during the neonatal period (days 1-30) had a pooled sensitivity of 91% (95% confidence interval [CI]: 87%-94%) and specificity of 51% (95% CI: 45%-58%). Late MRI (days 8-30) had higher sensitivity but lower specificity than early MRI (days 1-7). Proton MR spectroscopy deep gray matter lactate/N-acetyl aspartate (Lac/NAA) peak-area ratio (days 1-30) had 82% overall pooled sensitivity (95% CI: 74%-89%) and 95% specificity (95% CI: 88%-99%). On common study analysis, Lac/NAA had better diagnostic accuracy than conventional MRI performed at any time during neonatal period. The discriminatory powers of the posterior limb of internal capsule sign and brain-water apparent diffusion coefficient were poor.

CONCLUSIONS

Deep gray matter Lac/NAA is the most accurate quantitative MR biomarker within the neonatal period for prediction of neurodevelopmental outcome after NE. Lac/NAA may be useful in early clinical management decisions and counseling parents and as a surrogate end point in clinical trials that evaluate novel neuroprotective therapies.